1. 5/20/1999 Li-we Pan1 指導老師 ： 陳錫明教授 學生：潘立偉 學號： M8702048 日期： 5/20/1999 Myung-Kuk Park, Inbom Lee, Key-Mok Shon Expert Systems with Application 15(1998), p69~75 Using case-based reasoning for problem solving in a complex production process

2. 5/20/1999 Li-we Pan2 What is Case-Based Reasoning humans modify a strategy employed in a previously-solved problem to solve a new problem people reuse the problem solving experience to solve a new problem when a process engineer is confronted with a new problem, he can refer to similar cases and the suggested solution based on accumulated cases

3. 5/20/1999 Li-we Pan3 What can CBR do CBR is useful in explaining or justifying a solution Training time will be reduced for the novice process engineer because he can refer to the problem-solving history of experts

4. 5/20/1999 Li-we Pan4 Overview of the CBR Design-problem specification Design-case recall Design-case adaptation Design-problem solution Case library

5. 5/20/1999 Li-we Pan5 Case recall Design-problem specification To design case adaptation Design-case recall Case indexing Case retrieval Case selection

6. 5/20/1999 Li-we Pan6 Case adaptation From design- case adaptation Design-problem solution Design-case adaptation Solution proposal Solution evaluation Solution modification

7. 5/20/1999 Li-we Pan7 Description of the domain Knowledge Based Process Control Supporting System(KBPCS) & Deflection yoke(DY) & color display tube(CDT) quality of the DY depends on the coil winding process, which requires high expertise To provide visual aid for the process engineer of coil winding and to enhance the process control performance, KBPCS has the functions which handle massive variables and accumulates the expertise and information of the DY production process

8. 5/20/1999 Li-we Pan8 CBR applying factors in the production process Experts talk abort their domain by giving examples Experience is as valuable as textbook knowledge. Problems are not fully understood (weak technical models available).

9. 5/20/1999 Li-we Pan9 Cont. The DY production process has massive symptom lists (about 30) and process parameters (about 50). There is a need to build a corporate memory and transfer expertise among process engineers. To apply CBR, a large volume of historical cases should already exist.

10. 5/20/1999 Li-we Pan10 Define of a case every pattern consists of the observations form 17 check points. All the check points comprise six fields specifying the divergence of a pair of colors along the x- of y-axis. A case is composed of problem, adjustment, result, machine, and model use entity relationship (ER) model

11. 5/20/1999 Li-we Pan11 Retrieval k : the new problem j : the case problem i : the index (i=1, 2, …, n) Wi : weight factor which is given to the symptom i SM : the scaling measure

12. 5/20/1999 Li-we Pan12 Adaptation effective adaptation depends on –having both knowledge of possible adaptation – ways to select those that will be appropriate and effective in a particular situation

13. 5/20/1999 Li-we Pan13 STEP 1 Process engineer specifies the symptoms (S 1, S 2, …, S n for the new problem N) STEP 2 Search the cases (P) with S 1, S 2, …, S n where | α i -β i | ≦ ε i for all i, i = 1, 2, …,n. STEP 3 IF any case (P) exists THEN Search the solution PP for P from case database where GO STEP5 ELSE Search the case(P) where Search the solution PP for P form case database GO STEP 4 END IF

14. 5/20/1999 Li-we Pan14 STEP 4 Let IF PP’ > PP” THEN Solution = PP” ELSE Solution = PP’ END IF STEP 5 Display the solution parameter set and the similar cases  i = the S i value of the case(P)  i = the S i value of the N  i = the cognitive threshold of expert of S i  i = the desired value of S i ( the medium value within the specification) PP”= the maximum parameter set

15. 5/20/1999 Li-we Pan15 Advantage of using KBPCS Sharing of experience and knowledge Reducing training time for a novice Explicit and quick support problem-solving Utilizes CBR in assisting in the decision- marking process of process engineers in complex production processes